Обсуждение: RI status report #2
Man, that's a heap of additions.
> ATTENTION: catalog changes - initdb required!
>
> General support for deferred constraint triggers is finished
> and committed to CURRENT tree.
>
>
> Implemented so far:
>
> CREATE CONSTRAINT TRIGGER <constraint_name>
> AFTER <event> ON <relation_name>
> [ FROM <referencing_relation_name> ]
> [ [ NOT ] DEFERRABLE ]
> [ INITIALLY { IMMEDIATE | DEFERRED } ]
> FOR EACH ROW EXECUTE PROCEDURE <procedure_name> ( <args> )
>
> SET CONSTRAINTS { <constraint_names> | ALL } { IMMEDIATE | DEFERRED }
>
> Details on CREATE CONSTRAINT TRIGGER:
>
> <constraint_name>
>
> Can be a usual identifier or "" for unnamed
> constraints. Since the same constraint can result in
> multiple pg_trigger entries for different tables,
> there's no check for duplicates. This is the name to
> later identify constraints in SET CONSTRAINTS.
>
> FROM <referencing_relation_name>
>
> If given, causes that this trigger are automatically
> removed when the referencing relation is dropped.
> This is useful for referential action triggers (like
> ON DELETE CASCADE), which are fired on changes to the
> PK table. Dropping the FK table without removing the
> triggers from the PK table would make it unusable.
>
> [ NOT ] DEFERRABLE
>
> Specifies if the trigger is deferrable or not.
> Defaults to NOT DEFERRABLE if INITIALLY is IMMEDIATE.
> Defaults to DEFERRABLE if INITIALLY is DEFERRED.
>
> INITIALLY { IMMEDIATE | DEFERRED }
>
> Specifies the deferred state of the trigger at
> session start. Defaults to IMMEDIATE.
>
> <procedure_name> ( <args> )
>
> The usual trigger procedure definition.
>
> The trigger itself in pg_trigger is created with a tgname
> of RI_ConstraintTrigger_<newoid>, which should be unique
> enough.
>
> Details on SET CONSTRAINTS:
>
> <constraint_names>
>
> A comma separated list of constraint identifiers. An
> attempt to set named constraints to DEFERRED where at
> least one of the pg_trigger entries with this name
> isn't deferrable raises an ERROR.
>
> Using ALL with DEFERRED sets all deferrable
> constraint triggers (named and unnamed) to deferred,
> leaving not deferrable ones immediate.
>
> If SET CONSTRAINTS is used outside of a transaction block
> (BEGIN/COMMIT), it sets the default behaviour on session
> level. All constraint triggers begin each transaction
> (explicit block or implicit single statement) in these
> states.
>
> All AFTER ROW triggers (regular ones) are treated like
> IMMEDIATE constraint triggers now so they are fired at
> the end of the entire statement instead of during it.
> This interfered with the funny_dup17 test in the
> regression suite which is commented out now.
>
> Trigger events for deferred triggers are condensed during
> a transaction. That means, that executing multiple
> UPDATE commands affecting the same row would finally
> invoke only one trigger call which receives the original
> tuple (before BEGIN) as OLD and the final tuple (after
> last UPDATE) as NEW. Similar INSERT/DELETE of same row
> will fire no trigger at all.
>
> There are checks done if IMMEDIATE or BEFORE ROW triggers
> have already been fired when a row is touched multiple
> times in the same transaction. In that case, an error is
> raised because this might violate referential integrity.
>
> Needless to say that COMMIT causes an implicit SET
> CONSTRAINTS ALL IMMEDIATE. All deferred triggers are run
> then, so COMMIT could raise trigger generated errors now!
>
> Next we need:
>
> 1. Generic trigger procs that are argument driven. I'll make
> a separate thread for this topic.
>
> 2. Support in CREATE TABLE that issues the appropriate
> CREATE CONSTRAINT TRIGGER statements for FOREIGN KEY in
> the same manner as CREATE INDEX for PRIMARY KEY is done.
> This must wait until we have an accepted call interface
> for the generic trigger procs from 1..
>
> 3. Support for pg_dump to emit the correct CREATE CONSTRAINT
> TRIGGER statements. Who wants to pick up this topic?
>
> 4. Add the ability to swap out huge amounts of deferred
> trigger events to disk (actually I'm collecting them in
> memory - so large transactions affecting millions of rows
> of a table where triggers are defined are likely to blow
> up the backend). This is my topic - sorry.
>
> 5. Write a regression test for the new FOREIGN KEY support.
> Surely an important thing but one of the last steps after
> anything else works properly.
>
> 6. Remove the "not supported yet" note for FOREIGN KEY from
> the docs along with correcting to the full syntax
> supported finally :-)
>
> Hmmmm - the more I work on it the longer the TODO becomes.
>
>
> Jan
>
> --
>
> #======================================================================#
> # It's easier to get forgiveness for being wrong than for being right. #
> # Let's break this rule - forgive me. #
> #========================================= wieck@debis.com (Jan Wieck) #
>
>
>
> ************
>
--
Bruce Momjian | http://www.op.net/~candle
maillist@candle.pha.pa.us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026
> Bruce Momjian wrote: > > > > > > Man, that's a heap of additions. > > Only the top of the iceberg :-) Yikes. I was just talking to Thomas Lockhart by phone, and was saying that I thought 6.6 would be a small, incremental release after the changes in 6.5.*. Obviously, 6.6 is going to be as full-featured as earlier releases. -- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
Bruce Momjian wrote: > Yikes. I was just talking to Thomas Lockhart by phone, and was saying > that I thought 6.6 would be a small, incremental release after the > changes in 6.5.*. Obviously, 6.6 is going to be as full-featured as > earlier releases. And that surprises you?? Even in the short two years I've used PostgreSQL, I have grown accustomed to major changes every major version. First there was the NOT NULL (and scads of other) features to compel me to go from 6.1.1 to 6.2, then there were subselects (and vastly improved documentation) to get me up to 6.3, then there were views, rules, and the new protocol to make 6.4 a must-cc event, then MVCC.... And now I'm maintaining RPM's so I can stay on the released bleeding edge without breaking my server policies. Whoda thunk it? Of course, my measly list above doesn't do the development justice -- as one look at the changelog will show. Lamar Owen WGCR Internet Radio
> Bruce Momjian wrote: > > > Yikes. I was just talking to Thomas Lockhart by phone, and was saying > > that I thought 6.6 would be a small, incremental release after the > > changes in 6.5.*. Obviously, 6.6 is going to be as full-featured as > > earlier releases. > > And that surprises you?? Even in the short two years I've used > PostgreSQL, I have grown accustomed to major changes every major > version. First there was the NOT NULL (and scads of other) features to > compel me to go from 6.1.1 to 6.2, then there were subselects (and > vastly improved documentation) to get me up to 6.3, then there were > views, rules, and the new protocol to make 6.4 a must-cc event, then > MVCC.... And now I'm maintaining RPM's so I can stay on the released > bleeding edge without breaking my server policies. Whoda thunk it? > > Of course, my measly list above doesn't do the development justice -- as > one look at the changelog will show. Yes, it still shocks me. I was telling Thomas, every release I think, man, this is so great, no reason anyone should be using a prior release. And then the next release is the same thing. The basic issue for me is that each of the new features requsted looks so hard, I can't imagine how it could be done, but by release time, it does get done. Amazing. -- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
> > > > > Bruce Momjian wrote: > > > > > > > > > > > > Man, that's a heap of additions. > > > > > > Only the top of the iceberg :-) > > > > Yikes. I was just talking to Thomas Lockhart by phone, and was saying > > that I thought 6.6 would be a small, incremental release after the > > changes in 6.5.*. Obviously, 6.6 is going to be as full-featured as > > earlier releases. > > Wasn't it YOU who asked ME to become active again? Your > above thought is a little silly if ya really wanted to > interrupt my sleep mode ;-) I specialize in silly. :-) Full-featured is good, much better than small, incremental. I certainly interrupted your sleep mode. > > OTOH Vadim is close to WAL and I see activity on > (outer/left/right?) join support too. Maybe there wouldn't be > a v6.6 at all. Do I read 7.0 in there? > WAL is IMHO the only real reason not to choose PostgreSQL for > production. Beeing able to recover (roll forward) from a > backup using transaction log is a required feature for > mission critical data. Thus, having all this (WAL, FOREIGN > KEY etc.) is a greater step forward that that between v6.4 > and v6.5. > > If all that really materializes in our next release, it's > time to number it v7.0 - no? Yes, I am starting to see 7.0 too. -- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
Bruce Momjian wrote: > Lamr Owen wrote: > > And that surprises you?? Even in the short two years I've used > > PostgreSQL, I have grown accustomed to major changes every major [snip] > Yes, it still shocks me. I was telling Thomas, every release I think, > man, this is so great, no reason anyone should be using a prior release. > And then the next release is the same thing. > > The basic issue for me is that each of the new features requsted looks > so hard, I can't imagine how it could be done, but by release time, it > does get done. Amazing. I find the enthusiasm of this particular development quite infectious. While I'm only doing a very small part in packaging RPM's (thus far), I feel quite good about it (it conjures back the same feeling that I had at 15 years old when my Z80 disassembler first correctly disassembled the opcodes of three-quarters of the instruction set -- no operands at that time, but the opcode logic was WORKING... It felt uniquely gratifying). Just reading the web page and the release notes doesn't do this development justice -- until I subscribed to this hackers list, I had no idea that PostgreSQL development was so dynamic. This beats following the linux kernel development, IMO. Lamar Owen WGCR Internet Radio
On Wed, 29 Sep 1999, Bruce Momjian wrote:
> > Bruce Momjian wrote:
> > >
> > >
> > > Man, that's a heap of additions.
> >
> > Only the top of the iceberg :-)
>
> Yikes. I was just talking to Thomas Lockhart by phone, and was saying
> that I thought 6.6 would be a small, incremental release after the
> changes in 6.5.*. Obviously, 6.6 is going to be as full-featured as
> earlier releases.
Have we ever had a "small, incremental release", other then the
minor-minor releases? :)
Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy@hub.org secondary: scrappy@{freebsd|postgresql}.org
On Wed, 29 Sep 1999, Jan Wieck wrote:
> >
> > > Bruce Momjian wrote:
> > > >
> > > >
> > > > Man, that's a heap of additions.
> > >
> > > Only the top of the iceberg :-)
> >
> > Yikes. I was just talking to Thomas Lockhart by phone, and was saying
> > that I thought 6.6 would be a small, incremental release after the
> > changes in 6.5.*. Obviously, 6.6 is going to be as full-featured as
> > earlier releases.
>
> Wasn't it YOU who asked ME to become active again? Your
> above thought is a little silly if ya really wanted to
> interrupt my sleep mode ;-)
>
> OTOH Vadim is close to WAL and I see activity on
> (outer/left/right?) join support too. Maybe there wouldn't be
> a v6.6 at all.
>
> WAL is IMHO the only real reason not to choose PostgreSQL for
> production. Beeing able to recover (roll forward) from a
> backup using transaction log is a required feature for
> mission critical data. Thus, having all this (WAL, FOREIGN
> KEY etc.) is a greater step forward that that between v6.4
> and v6.5.
>
> If all that really materializes in our next release, it's
> time to number it v7.0 - no?
I was kinda starting to wonder that one myself... my feeling: its time
guys.
We're still in no more rush to get it out the door...sometime 1st quarter
of year 2000, but with everything that has changed up until now, I think
its time we up'd the major version number ...
Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy@hub.org secondary: scrappy@{freebsd|postgresql}.org
On Wed, 29 Sep 1999, Bruce Momjian wrote:
> Yes, I am starting to see 7.0 too.
one motion, two second's...anyone disagree? *lifts mallet*
Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy@hub.org secondary: scrappy@{freebsd|postgresql}.org